GB1589933A

GB1589933A - Amino acid derivatives

Info

Publication number: GB1589933A
Application number: GB45787/77A
Authority: GB
Original assignee: ER Squibb and Sons LLC
Current assignee: ER Squibb and Sons LLC
Priority date: 1976-12-03
Filing date: 1977-11-03
Publication date: 1981-05-20
Also published as: US4154736A; JPS6121226B2; DE2753824A1; JPS5371015A; US4091024A; US4128721A; FR2372804B1; US4127729A; CA1080728A; FR2372804A1

Description

PATENT SPECIFICATION ( 11) 1 589 933

( 21) Application No 45787/77 ( 22) Filed 3 Nov 1977 ( 31) Convention Application No 747282 ( 32) Filed 3 Dec 1976 in ( 33) United States of America (US) ( 44) Complete Specification published 20 May 1981 ( 51) INT CL 3 C 07 C 149/243 A 61 K 31/40 31/195 C 07 D 207/16 ( 52) Index at acceptance C 2 C 1341 1343 1410 1532 20 Y 213 215 220 226 227 22 Y 234 240 246 247 250 251 252 28 X 292 29 Y 304 30 Y 313 316 31 Y 320 321 326 32 Y 339 342 34 Y 351 352 355 360 361 362 365 366 367 368 36 Y 370 371 373 37 Y 380 390 440 491 554 556 571 574 57 X 57 Y 581 584 591 596 601 612 620 625 62 X 635 638 63 X 648 64 X 656 658 65 Y 662 672 675 678 682 75 X 76 Y 771 78 X 802 80 Y AA CH QU QZ RC RE RF RQ SL ( 72) Inventor MIGUEL ANGEL ONDETTI ( 54) AMINO ACID DERIVATIVES ( 71) We, E R SQUIBB & SONS INC, a corporation organised and existing under the laws of the State of Delaware, United States of America, of Lawrenceville-Princeton Road, Princeton, New Jersey, United States of America, do hereby declare the invention for which we pray that a patent may be granted to us, and the method by which it is to be performed, to be particularly described in

and by the following statement:-

This invention provides derivatives of amino acids which have the general formula X (I) (CH,) A B R,-S-(CH 2)m CH CO-N-CH-CO-R and salts thereof wherein R is hydroxy or lower alkoxy; R, is hydrogen, lower alkanoyl benzoyl or X (CH 2) A B -S-CH 2)-CH-CO-N-cH-C-RI I -S CH 2)m-CH-CO NCH-CO-R A is hydrogen, lower alkyl or hydroxy lower alkyl; B is hydrogen, lower alkyl, phenyl, phenyl lower alkyl, hydroxy lower alkyl, hydroxy phenyl lower alkyl, amino lower alkyl, guanidino lower alkyl, mercapto lower alkyl, lower alkyl thio lower alkyl, imidazolyl lower alkyl, indolyl lower alkyl, carbamoyl lower alkyl or carboxy lower alkyl, or A and B together form a (CH 2)p bridge which completes a ring of 5 or 6 atoms with the nitrogen and carbon to which they are joined, one carbon optionally bearing a hydroxy group; X is carboxy, lower alkoxycarbonyl, carbamoyl, N-substituted carbamoyl (as herein after defined) or cyano; m is 0 or 1; n is 0, 1, 2, 3 or 4; and p is 3 or 4.

The asterisks denote centers of asymmetry.

The invention also extends to pharmaceutical compositions comprising such compounds and a pharmaceutical carrier.

Compounds in the group represented by formula I which are derived from or include the structure of the amino acids glycine, alanine, leucine, threonine, phenylglycine, phenyl alanine, lysine, arginine, glutamine, histidine, methionine, serine, cysteine, tyrosine, valine, asparagine, glutamic acid, proline, hydroxyproline, or tryptophane are broadly preferred Preferred modifications are 5 compounds of formula I wherein R is hydroxy; R, is hydrogen or lower alkanoyl (particularly hydrogen or acetyl); X is lower alkoxycarbonyl or carbamoyl; A is hydrogen or joins in a 5 or 6-membered ring with B, especially a 5membered ring; B is lower alkyl, aminolower alkyl or phenyl-lower alkyl or joins in a ring with A, especially a 5-membered ring; m is I; and N is I or 2 10 Especially preferred are those compounds of formula I which are derived from proline and have the formula -5 c O -Ce O- (CThe symbols have the same preferred meanings described above.

The lower alkyl groups represented by any of the variables are straight and 15 branched chain hydrocarbon radicals from methyl to heptyl, for example, methyl, ethyl, propyl, isopropyl, butyl, isobutyl, t-butyl, pentyl, and isopentyl Similarly, the lower alkoxy groups are lower alkyl groups with a link to oxygen, for e (ample, methoxy, ethoxy, propoxy, isopropoxy, butoxy, isobutoxy and t-butoxy The C,-C 4 members, especially C 1 and C 2 members, of all types are preferred Benzyl is the 20 preferred phenyl-lower alkyl group and methoxy and t-butoxy the preferred lower alkoxy groups The lower alkanoyl groups are the acyl radicals of the lower (up to 7 carbons) fatty acids, e g, acetyl, propionyl, and butyryl, acetyl being preferred.

The N-substituted carbamoyl groups represented by X are carbamoyl radicals bearing on the nitrogen a lower alkyl or a phenyl-lower alkyl substituent 25 The products of formula I and the preferred subgroups can be produced by various methods of synthesis.

According to a preferred method, the amino acid of the formula A B I I (III) HN-CH-CO-R wherein A and B are defined as above, and R is hydroxy is acylated with an acid of 30 the formula X (IV) (CH 2), (IV) R,-S-CH 2)m-CH-COOH wherein R 1, m and N have the meaning defined above and X is other than carboxyl, by one of the known procedures in which the acid IV is activated, prior to reaction with the acid III, involving formation of a mixed anhydride, symmetrical 35 anhydride, acid chloride, active ester, Woodward reagent K, N,N' carbonylbisimidazole or EEDQ (N ethoxycarbonyl 2 ethoxy 1,2 dihydro quinoline) When R is lower alkoxy, this or other known methods of coupling such moieties can be used lFor a review of these methods, see Methoden der Organischen Chemie (Houben-Weyl) Vol XV, parts I and 2 ( 1974)l 40 Compounds of formula I wherein X is -CONH 2 and R is hydroxy can also be produced by ammonolysis of those compounds of formula I wherein X is lower alkoxycarbonyl.

Compounds of formula I wherein m is 0 can also be produced by acylation of the acid of formula II with an acid of the formula 45 X I (CH 2)C (V) Hal-CH-COOH 1.589 933 3 1,589,933 3 wherein Hal represents halogen, preferably chlorine or bromine, followed by displacement with a thiol acid of the formula (VI) R-COSH When the product obtained is an ester, e g, R, is lower alkoxy, the ester can be converted to the free carboxy group by saponification or, when R 1 is a tertiary 5 lower alkoxy group, e g, t-butoxy, by treatment with trifluoroacetic acid and anisole Conversely the free acid can be esterified by conventional procedures.

The disulfides of formula I, wherein R, is X (CH 2)n A B -S-(CH,),-C Ht-u O-N-CH-COR are obtained by oxidation of the compound of the formula 10 X (CH 2)n A B (VII) IS-CH,)6-CH-CO-N-CH-COR e.g, with an alcoholic solution of iodine.

Products of formula I have two asymmetric carbon atoms These carbon atoms are indicated by an asterisk in formula I The compounds accordingly exist in diastereo-isomeric forms or in racemic mixtures thereof All of these are within the 15 scope of the invention The above described syntheses can utilize the racemate or one of the enantiomers as starting material When the racemic starting material is used in the synthetic procedure, the stereo-isomers obtained in the product can be separated by conventional chromatographic or fractional crystallization methods.

In general, the L isomer with respect to the carbon of the amino acid constitutes 20 the preferred isomeric form.

The compounds of this invention form basic salts with various inorganic and organic bases which are also within the scope of the invention Such salts include ammonium salts, alkali metal salts e g sodium and potassium salts (which are preferred), alkaline earth metal salts e g the calcium and magnesium salts, salts 25 with organic bases, e g, dicyclohexylamine salt, benzathine, N methyl d glucamine, hydrabamine salts, salts with amino acids e g arginine and lysine The non-toxic, physiologically acceptable salts are preferred, although other salts are also useful, e g, in isolating or purifying the product.

The salts are formed in conventional manner by reacting the free acid form of 30 the product with one or more equivalents of the appropriate base providing the desired cation in a solvent or medium in which the salt is insoluble, or in water and removing the water by freeze drying By neutralizing the salt with an insoluble acid such as a cation exchange resin in the hydrogen form le g, polystyrene sulfonic acid resin Dowex 50 Trade Mark (Mikes, Laboratory Handbook of 35 Chromatographic Methods (Van Nostrand, 1961) page 2561 or with an aqueous acid and extraction with an organic solvent, e g, ethyl acetate, dichloromethane or the like, the free acid form can be obtained, and, if desired, another salt formed.

Additional experimental details are found in the Examples which are preferred embodiments and also serve as models for the preparation of other members of the 40 group.

Compounds of this invention have been found to inhibit the conversion of the decapeptide angiotensin I to angiotensin II and may therefore be used in reducing or relieving angiotensin related hypertension The action of the enzyme renin on angiotensinogen, a pseudoglobulin in blood plasma, produces angiotensin I 45 Angiotensin I is converted by angiotensin converting enzyme (ACE) to angiotensin II The latter is an active pressor substance present which has been implicated as the causative agent in various forms of hypertension in various mammalian species, e.g, rats and dogs The compounds of this invention intervene in the angiotensinogen-eangiotensin I-angiotensin II sequence by inhibiting angiotensin 50 converting enzyme and reducing or eliminating the formation of the pressor substance angiotensin II.

The inhibition of the angiotensin converting enzyme by compounds of formula I can be measured in vitro with isolated angiotensin converting enzyme from rabbit lungs following the procedure described by Cushman and Cheung Biochem 5 Pharmacol, 20, 1637 ( 1971)l, and with an excised smooth muscle assay lE.

O'Keefe, et al, Federation Proc 31, 511 ( 1972)l in which these compound have been shown to be powerful inhibitors of the contractile activity of angiotensin I and potentiators of the contractile activity of bradykinin.

The administration of a composition containing one or a combination of 10 compounds of formula I or physiologically acceptable salt thereof to the species of hypertensive mammal alleviates or reduces angiotensin dependent hypertension A single dose, or preferably two to four divided daily doses, provided on a basis of e g.

to 1000 mg per kilogram per day, preferably 10 to 500 mg per kilogram per day is appropriate to reduce blood pressure The animal model experiments described by 15 S L Engel, T R Schaeffer, M H Waugh and B Rubin, Proc Soc Exp Biol.

Med 143, ( 1973) serve as a useful guide.

The substance is preferably administered orally, but parenteral routes such as subcutaneously, intramuscularly, intravenously or intraperitoneally can also be employed 20 The compounds of this invention can be utilized to achieve the reduction of blood pressure by formulating in compositions such as tablets, capsules or elixirs for oral administration or in sterile solution or suspensions for parenteral administration For example 10 to 500 mg of a compound or mixture of compounds of formula I or physiologically acceptable salt is compounded with a 25 physiologically acceptable vehicle, carrier, excipient, binder, preservative, stabilizer or flavor, in a unit dosage form as called for by accepted pharmaceutical practice The amount of active substance in these compositions or preparations is such that a suitable dosage in the range indicated is obtained.

The following Examples are illustrative of the invention; Examples 1, 7-9, 11, 30 13 and 28 describe the preparation of intermediates All temperatures are in degrees celsius.

Example I

3-Acetylthio-2-methoxycarbonylmethylpropanoic acid A mixture of thiolacetic acid ( 12 5 g) and 3 methoxycarbonyl 2 35 methylenepropanoic acid ( 17 1 g) are heated on the steam bath for two hours The reaction is concentrated in vacuo and the residue is dissolved in ethyl acetate ( 125 ml.) and dicyclohexylamine ( 35 ml) is added The crystals are filtered, dried and recrystallized from ethyl acetate to yield 37 8 g, m p 120-121 This dicyclohexylammonium salt of 3 acetyl thio 2 40 methoxycarbonylmethylpropanoic acid is converted to the free acid by distribution between a system of ethyl acetate and 10 % aqueous potassium bisulfate.

Example 2

1-l 3 (Acetylthio)-2-(methoxycarbonylmethyl)propanoyllL-proline tert-butyl ester 45 To a solution of L-proline tert-butyl ester ( 1 71 g) and 3hydroxybenzotriazole ( 1.35 g) in dichloromethane ( 15 ml), dicyclohexylcarbodiimide ( 2 06 g) and 3 acetyl thio 2 methoxycarbonylmethylpropanoic acid ( 2 2 g) are added After 18 hours stirring at room temperature, the precipitate formed is filtered off, the filtrate is washed neutral, dried, and concentrated to dryness to yield 3 7 g of I 50 l 3 (acetylthio) 2 (methoxycarbonylmethyl) propanoyll L proline tert butyl ester Rf: 0 8 (silica gel-ethyl acetate).

Example 3

1-l 3-(Acetylthio)-2-(methoxycarbonylmethyl)propanoyll-Lproline 55 1 l 3 (Acetylthio) 2 (methoxycarbonylmethyl)propanoyll L proline tert-butylester ( 2 9 g) is dissolved in a mixture of trifluoroacetic acid ( 17 5 ml) and anisole 8 4 ml) After one hour storage at room temperature the excess trifluoroacetic acid is removed in vacuo and the residue is precipitated twice from ether-hexane to yield 2 1 g of 1 l 3 (acetylthio) 2 60 (methoxycarbonylmethyl) propanoyll L proline Rf= 0 4 (silica gelbenzene:acetic acid 75:25).

1.589 933 Example 4

I -l 3-Mercapto-2-(methoxycarbonylmethyl)propanoyll-L-proline I l 3 (Acetylthio) 2 (methoxycarbonylmethyl)propanoyll L proline ( 2.1 g) is dissolved in a mixture of water ( 35 ml) and concentrated ammonia ( 35 ml) under a blanket of argon After twenty minutes, the solution is chilled in an ice 5 bath, made acidic with concentrated hydrochloric acid, saturated with sodium chloride and extracted with ethyl acetate The organic layer is dried and concentrated to dryness in vacuo to yield 1 1 g of I l 3 mercapto 2 (methoxycarbonylmethyl)propanoyll L proline that is purified by chromatography on silica gel (benzene:acetic acid 75:25) Rf:0 35 (silica gel, 10 benzene:acetic acid, 75:25).

Example 5

1 -l 2-Carboxymethyl-3-mercaptopropanoyll L-proline To a solution of I l 3 (acetylthio) 2 (methoxycarbonylmethyl)propanoyll L proline ( 3 g) in methanol ( 60 ml), N 15 sodium hydroxide ( 60 ml) is added After four hours, the solution is applied to a column of Dowex 50 ion exchange resin in the hydrogen cycle, and the desired material is eluted with water to yield 2 3 g of I l 2 carboxymethyl 3 mercaptopropanoyll L proline Rf:0 2 (silica gel, benzene:acetic acid 75:25).

Example 6 20

1 -l 2-Carbamoylmethyl-3-mercaptopropanoyll -L-proline A) I l 3 (Acetylthio) 2 (methoxycarbonylmethyl)propanoyll L proline ( 2 1 g) is dissolved in a mixture of water ( 40 ml) and concentrated ammonia ( 40 ml) After one hour the reaction mixture is concentrated to 1/3 volume, and applied to a column of Dowex 50 resin in the hydrogen cycle The 25 product is eluted with water The aqueous is extracted with ethyl acetate and then concentrated to dryness to yield 1 4 g of I l 2 carbamoylmethyl 3 mercaptopropanoyll L proline Rf:0 50 (silica gel, chloroform:methanol:acetic acid:water).

B) 1 l 2 Carbamoylmethyl 3 acetylthiopropanoyll L proline ( 1 2 g) 30 is dissolved in a mixture of water ( 20 ml) and concentrated ammonia ( 20 ml) After minutes the reaction mixture is processed as described in "A" above to obtain I l 2 carbamoylmethyl 3 mercaptopropanoyll L proline.

Example 7

3-Acetylthio-2-carbamoylmethylpropanoic acid 35 By substituting 3 carbamoyl 2 methylenepropanoic acid for the 3 methoxycarbonyl 2 methylenepropanoic acid in the procedure of Example 1, 3 acetylthio 2 carbamoylmethyl propanoic acid is obtained, m p 1101110.

Example 8 40

3-Acetylthio-2-cyanomethylpropanoic acid Dicyclohexylcarbodiimide ( 1 03 g) is added to a solution of 3 acetylthio 2 carbamoylmethylpropanoic acid ( 1 02 g) in pyridine ( 18 ml) After five hours stirring at room temperature, the precipitate is filtered off and the filtrate is concentrated to dryness, the residue is dissolved in ethyl acetate and extracted with 45 saturated aqueous bicarbonate The aqueous phase is acidified and extracted with ethyl acetate This organic layer is dried and concentrated to dryness The residue, 3 acetylthio 2 cyanomethylpropanoic acid is crystallized from etherhexane, m.p 110-112 .

Example 9 50

3-Acetylthio-2-(methoxycarbonylmethyl)propanoic acid N-hydroxysuccinimido ester To a solution of 3 acetylthio 2 (methoxycarbonylmethyl) propanoic acid ( 5 5 g) and N-hydroxysuccinimide ( 2 9 g) in tetrahydrofuran ( 100 ml) chilled in an ice bath, dicyclohexylcarbodiimide ( 5 15 g) is added The reaction mixture is 55 stirred for 15 hours at 5 , filtered and the filtrate is concentrated to dryness in vacuo to yield 3 acetylthio 2 (methoxycarbonylmethyl)propanoic acid Nhydroxysuccinimido ester.

Example 10

1-l 2-(Carbamoylmethyl)-3-(acetylthio)propanoyll-L-proline 60 By substituting 3 acetylthio 2 (carbamoylmethyl)propanoic acid for the 3 (acetylthio) 2 (methoxycarbonylmethyl) propanoic acid in the procedure s 1,589,933 of Example 2, and then submitting the product of the procedure of Example 3, 1 l 2 (carbamoylmethyl) 3 (acetylthio)propanoyll L proline tert-butyl ester and 1 l 2 (carbamoylmethyl) 3 (acetylthio) propanoyll L proline are obtained.

Example 11 5

3-Acetylthio-2-l(N-butylcarbamoyl)methyllpropanoic acid By substituting 3 (N butylcarbamoyl) 2 methylene propanoic acid for the 3 methoxycarbonyl 2 methylenepropanoic acid in the procedure of Example 1, 3 acetylthio 2 l(N butylcarbamoyl)methyllpropanoic acid is obtained 10 Example 12

I -l 3-(Acetylthio)-2-lN-butylcarbamoyl)methyllpropanoyl-L-proline By substituting 3 (acetylthio) 2 l(N-butylcarbamoyl) methyllpropanoic acid for the 3 (acetylthio) 2 (methoxy carbonylmethyl)propanoic acid in the procedure of Example 2 and then submitting the product to the procedure of 15 Example 3, 1 l 3 (acetylthio) 2 l(N butylcarbamoyl)methyll propanoyl L proline is obtained.

Example 13

2-Methylene-4-(ethoxycarbonyl)butyric acid A mixture of 2-methyleneglutaric acid lBer 34, 427 ( 1901)1 ( 40 g) and acetyl 20 chloride ( 80 ml) is heated on the steam bath for 1 5 hours The excess acetyl chloride is removed in vacuo ( 75 ) and the residue is evaporated from toluene twice.

Finally, the residue is dissolved in ethanol and heated on the steam bath for one hour The reaction mixture is concentrated to dryness to yield 2 methylene 4 (ethoxycarbonyl)butyric acid 25 Example 14

1 -l 2-Mercaptomethyl-4-(ethoxycarbonyl)butanoyll-L-proline By substituting 2 methylene 4 (ethoxycarbonyl)butyric acid for the 3 methoxycarbonyl 2 methylenepropanoic acid in the procedure of Example 1, and then submitting the product to the procedure of Examples 2, 3 and 4, 2 30 acetylthiomethyl 4 (ethyoxycarbonyl)butyric acid, 1 l 2 (acetylthio) methyl 4 (ethoxycarbonyl)butanoyll L proline tert-butyl ester, 1 l( 2 acetylthiomethyl) 4 (ethoxycarbonyl) butanoyll L proline and 1 l 2 mercaptomethyl 4 (ethoxy carbonyl)butanoyll L proline are obtained.

Example 15 35

I -l 3 Mercapto-2-(cyanomethyl)propanoyll -L-proline By substituting 3 acetylthio 2 cyanomethylpropanoic acid for the 3 (acetylthio) 2 (methoxycarbonylmethyl)propanoic acid in the procedure of Example 2, and then submitting the product to the procedures of Examples 3 and 4, 1 l 3 (acetylthio) 2 (cyanomethyl)propanoyll L proline tertbutyl ester, 40 1 l 3 (acetylthio) 2 (cyanomethyl)propanoyll L proline and I l 3 mercapto 2 (cyanomethyl)propanoyll L proline are obtained.

By treating this product with an equivalent proportion of sodium hydroxide solution, then removing the water by freeze drying, the sodium salt is obtained.

Example 16 45

1,1 '-lDithiobis-l 2-(methoxycarbonylmethyl)-3-propanoylll bis-L-proline To a solution of 1 l 3 mercapto 2 (methoxycarbonylmethyl) propanoyll L proline ( 1 g) in water ( 20 ml), and alcoholic solution of iodine is added until persistent yellow color, while maintaining the p H between 5 and 7 by 50 careful addition of N sodium hydroxide The yellow color is discharged by addition of a few drops of aqueous sodium thiosulfate and after acidification with concentrated hydrochloric acid, the reaction mixture is extracted with ethyl acetate The organic layer is dried and concentrated to dryness in vacuo to yield 1,1 ' ldithiobis l 2 (methoxycarbonylmethyl) 3 propanoylll bis L 55 proline.

Example 17

N'-l 3-(Acetylthio)-2 (methoxycarbonylmethyl)propanoyl)-L arginine A solution of 3 (acetylthio) 2 (methoxycarbonylmethyl) propanoic 60 acid N hydroxysuccinimide ester ( 1 67 g) in ethanol ( 17 ml) is added dropwise to a solution of L-arginine ( 0 9 g), and sodium bicarbonate ( 1 26 g) in water ( 12 ml).

1.589933 7 1,589,933 7 The mixture is stirred at room temperature for 16 hours, and then extracted with ethyl acetate The aqueous layer is applied to a column of Dowex 50 resin in the hydrogen cycle, and eluted with water until no more acidic material is eluted Na l 3 (acetylthio) 2 (methoxycarbonylmethyl) propanoylll L arginine is then eluted with pyridine acetate buffer at p H 6 5 5 Example 18

Na-l 3-Mercapto-2-(methoxycarbonylmethyl)propanoyll -L arginine To a solution of Na l 3 (acetylthio) 2 (methoxy carbonymethyl)propanoyll L arginine ( 1 9 g) in methanol ( 10 ml), sodium 10 methoxide ( 0 56 g) is added After ten minutes, the solution is applied to a column of Dowex 50 resin and the column is washed with water until no more acidic material is eluted Na l 3 mercapto 2 (methoxycarbonylmethyl)propanoyll L arginine is then eluted with a pyridine-acetate buffer of p H 6 5.

Example 19 15

N l 3-Mercapto-2-(carbamoylmethyl) propanoyll-L-arginine By substituting Na l 3 (acetylthio) 2 (methoxycarbonylmethyl)propanoyll L argine for the I l 3 (acetylthio 2 (methoxycarbonylmethyl)propanoyll L proline in the procedure of Example 6 A, and then isolating the product with Dowex 50 resin as described in the 20 procedure of Example 17, Na l 3 mercapto 2 (carbamoylmethyl)propanoyll L arginine is obtained.

Example 20

N l 3-Mercapto-2-(methoxycarbonylmethyl)propanoyll-Lhistidine 25 By submitting L-histidine for the L-arginine in the procedure of Example 17, and then submitting the product to the procedure of Example 18, Na l 3 (acetylthio) 2 methoxycarbonylmethyl)propanoyll L histidine and Na l 3 mercapto 2 (methoxycarbonylmethyl)propanoyll L histidine are obtained.

Example 21 30

N' l 3 Mercapto-2-(carbamoylmethyl)propanoyll-L-histidine By substituting N O l 3 (acetylthio) 2 methoxycarbonylmethyl)propanoyll L histidine for the N O l 3 (acetylthio) 2 (methoxycarbonylmethyl)propanoyll L arginine in the procedure of Example 19, N l 3 mercapto 2 (carbamoylmethyl) propanoyll L 35 histidine is obtained.

Example 22

N-l 3-Mercapto-2-(methoxycarbonylmethyl)propanoyll -L-alanine By substituting L-alanine tert-butyl ester for the L-proline tert-butyl ester in the procedure of Example 2, and then submitting the product to the procedure of 40 Examples 3 and 4, N l 3 mercapto 2 (methoxycarbonylmethyl)propanoyll L alanine is obtained.

Example 23

N l 2-(Carbamoylmethyl)-3-mercaptopropanoyll-L-alanine By substituting L-alanine tert-butyl ester for the L-proline tert-butyl ester in 45 the procedure of Example 2, and then submitting the product to the procedures of Examples 3 and 6, N l 2 (carbamoylmethyl) 3 mercaptopropanoyll L alanine is obtained.

Example 24

N-l 3-Mercapto-2-(methoxycarbonylmethyl)propanoyll-L 50 asparagine By substituting L-asparagine tertbutyl ester for the L-proline tert-butyl ester in the procedure of Example 2, and then submitting the product to the procedure of Examples 3 and 4 N l 3 mercapto 2 (methoxycarbonylmethyl)propanoyll L asparagine is obtained 55 Example 25

N-l 2-(Carbamoylmethyl)-3-mercaptopropanoyll -L-glutamine By substituting L-glutamine tertbutyl ester for the L-proline tert-butyl ester in the procedure of Example 2, and then submitting the product to the procedures of Examples 3 and 6 A, N l 2 (carbamoylmethyl) 3 mercaptopropanoyll L glutamine is obtained.

Example 26

N-l 3-Mercapto-2-(methoxycarbonylmethyl)propanoyl-L5aspartic acid 5 By substituting L-aspartic acid di-tert-butyl ester for the L-proline tert-butyl ester in the procedure of Example 2, and then submitting the product to the procedure of Examples 3 and 4, N l 3 mercapto 2 (methoxycarbonylmethyl) propanoyll L aspartic acid is obtained.

Example 27 10

N-l 2-(Carbamoylmethyl)-3-mercaptopropanoyll-L-glutamic acid By substituting L-glutamic acid di-tert-butyl ester for the L-proline tert-butyl ester in the procedure of Example 2, and then submitting the product to the procedure of Examples 3 and 6 A, N l 2 (carbamoylmethyl) 3 mercapto propanoyll L glutamic acid is obtained 15 Example 28

N-l 3-(Acetylthio)-2-(methoxycarbonylmethyl)propanoyll -S(N-ethylcarbamoyl)-L-cysteine A solution of 3 (acetylthio) 2 (methoxycarbonylmethyl) propanoic acid N-hydroxysuccinimido ester ( 1 67 g) in ethanol ( 17 ml) is added dropwise to a 20 solution of S (N ethylcarbamoyl) L cysteine ( 1 g) and sodium bicarbonate ( 1.26 g) in water ( 12 ml) The mixture is stirred at room temperature for sixteen hours and then is extracted with ethyl acetate The aqueous layer is acidified and extracted with ethyl acetate This second organic layer is dried and concentrated to dryness in vacuo to yield N l 3 (acetylthio) 2 25 (methoxycarbonylmethyl)propanoyll S (N ethylcarbamoyl) L cysteine.

Example 29

N-l 3-Mercapto-2-(methoxycarbonylmethyl)propanoyll-Lcysteine To a solution of N l 3 (acetylthio) 2 30 (methoxycarbonylmethyl)propanoyll S (N ethylcarbamoyl) L cysteine ( 1.9 g) in methanol ( 10 ml), sodium methoxide ( 0 84 g) is added After thirty minutes, the solution is diluted with 0 1 N hydrochloric acid and extracted with ethyl acetate The organic layer is dried and concentrated to dryness in vacuo to yield N l 3 mercapto 2 (methoxycarbonylmethyl)propanovll L cysteine 35 Example 30

N 0-l 3-(Acetylthio)-2-(methoxycarbonylmethyl)propanoyll-Llysine By substituting NE tert butyloxycarbonyl L lysine tert-butyl ester for the L-proline tert-butyl ester in the procedure of Example 3, followed by isolation 40 with Dowex 50 resin as described in Example 17, N" l 3 (acetylthio) 2 (methoxycarbonylmethyl)propanoyll L lysine is obtained.

Example 31

Na-l 3-Mercapto-2-(methoxycarbonylmethyl)propanoyll-L-lysine By substituting N l 3 (acetylthio) 2 45 (methoxycarbonylmethyl)propanoyll L lysine for the Na l 3 (acetylthio) 2 (methoxycarbonylmethyl)propanoyll L arginine in the procedure of Example 18, N" l 3 mercapto 2 (methoxycarbonylmethyl)propanoyll L lysine is obtained.

Example 32 50

N"-l 2-(Carbamoylmethyl)-3-mercaptopropanoyll-L-lysine By substituting N" l 3 (acetylthio) 2 methoxycarbonylmethylpropanoyll L lysine for the N O l 3 acetylthio 2 methoxycarbonylmethylpropanoyll L arginine in the procedure of Example 19, N" l 2 (carbamoylmethyl) 3 mercaptopropanoyll L lysine is obtained 55 Example 33

N-l 3-Mercapto-2-(methoxycarbonylmethyl)propanoyll-L-methionine By substituting L-methionine diphenylmethyl ester for the L-proline tertbutyl ester in the procedure of Example 2, and then submitting the product to the 1,589,933 procedure of Examples 3 and 4, N l 3 mercapto 2 (methoxycarbonylmethyl) propanoyll L methionine is obtained.

Example 34

N-l 2-(carbamoylmethyl)-3-mercaptopropanoyll-L-methionine By substituting L-methionine diphenylmethyl ester for the L-proline tertbutyl 5 ester in the procedure of Example 2, and then submitting the product to the product to the procedure of Examples 3 and 6 A, N l 2 (carbamoylmethyl) 3 mercaptopropanoyll L methionine is obtained.

Example 35

N-l 3-Mercapto-2-(methoxycarbonylmethyl)propanoyl)-L 10 phenylalanine By substituting L-phenylalanine tert-butyl ester for the L-proline tertbutyl ester in the procedure of Example 2, and then submitting the product to the procedure of Examples 3 and 4, N l 3 mercapto 2 (methoxycarbonylmethyl)propanoyll L phenylalanine is obtained 15 Example 36

N-l 2-(Carbamoylmethyl)-3-mercaptopropanoyll -L-phenylalanine By substituting L-phenylalinine tert-butyl ester for the L-proline tertbutyl ester in the procedure of Example 2, and then submitting the product to the procedure of Examples 3 and 6 A, N l 2 (carbamoylmethyl) 3 20 mercaptopropanoyll L phenylalanine is obtained.

Example 37 1 -l 3-Mercapto-2 (methoxycarbonylmethyl)propanoyll-4-hydroxy

L-proline By substituting 4 hydroxy L proline p methoxy benzyl ester for the L 25 proline tert-butyl ester in the procedure of Example 2, and then submitting the product to the procedures of Examples 3 and 4, 1 l 3 mercapto 2 (methoxycarbonylmethyl)propanoyll 4 hydroxy L proline is obtained.

Example 38

1-l 2-Carbamoylmethyl-3-mercaptopropanoyll-5-hydroxy-L 30 pipecolic acid By substituting 5 hydroxy L pipecolic acid for the S (N ethylcarbamoyl) L cysteine in the procedure of Example 28, and then submitting the product to the procedure of Example 6 A, I l 2 carbamoylmethyl 3 mercaptopropanoyll 5 hydroxy L pipecolic acid is 35 obtained.

Example 39

1 l 3-Mercapto-2-(methoxycarbonylmethyl)propanoyll -Lpipecolic acid By substituting L-pipecolic acid tert-butyl ester (prepared from Lpipecolic 40 acid as described for L-proline) for the L-proline tert-butyl ester in the procedure of Example 2, and then submitting the product to the procedure of Examples 3 and 4, 1 l 3 mercapto 2 (methoxycarbonylmethyl) propanoyll L pipecolic acid is obtained.

Example 40 45

N-l 3-Mercapto-2-(methoxycarbonylmethyl)propanoyll-L-serine By substituting O tert butyl L serine tert-butyl ester for the L-proline tert-butyl ester in the procedure of Example 2, and then submitting the product to the procedure of Examples 3 and 4, N l 3 mercapto 2 (methoxycarbonylmethyl)propanoyll L serine is obtained 50 Example 41

N-l 2-(Carbamoylmethyl)-3-mercaptopropanoyll-L-threonine By substituting O tert butyl L threonine tert-butyl ester for the Lproline tert-butyl ester in the procedure of Example 2, and then submitting the product to the procedures of Examples 3 and 6 A, N l 2 (carbamoylmethyl) 3 55 mercaptopropanoyll L threonine is obtained.

1,589,933 Example 42

N-l 3 Mercapto-2-(methoxycarbonylmethyl)propanoyll -Ltyrosine By substituting L-tyrosine for the S (N ethylcarbamoyl) L cysteine in the procedure of Example 28, and then submitting the product to the procedure of 5 Example 29, N l 3 mercapto 2 (methoxycarbonylmethyl)propanoyll L tyrosine is obtained.

Example 43 n 0-l 3-Mercapto-2-(methoxycarbonylmethyl)propanoyll-Ltryptophane lo By substituting L-tryptophane for the S (N ethylcarbamoyl) L cysteine in the procedure of Example 28, and then submitting the product to the procedure of Example 29, Na l 3 mercapto 2 (methoxycarbonylmethyl)propanoyll L tryptophane is obtained.

Example 44 15

N,NNlDithiobis-( 2-methoxycarbonylmethyl)-3-propanoyll-bisL-lysine By substituting N l 3 mercapto 2 (methoxycarbonylmethyl) propanoyll L lysine for the 1 l 3 mercapto 2 (methoxycarbonylmethyl)propanoyll L proline in the procedure of Example 16, 20 and isolating the product with a Dowex 50 resin as described in the procedure of Example 18, N%,N' ldithiobis ( 2 methoxycarbonylmethyl) 3 propanoyll bis L lysine is obtained.

Example 45

1-l 2-(Benzoylthio)-3-(methoxycarbonyl)propanoyll-L-proline 25 L-Proline ( 5 75 g) is dissolved in aqueous N sodium hydroxide ( 50 ml) and the solution is chilled in an ice bath with stirring 2 N Sodium hydroxide ( 25 ml) and 2 bromo 3 (methoxycarbonyl)propionyl chloride ( 11 6 g) are added in that order and the mixture is removed from the ice bath and stirred at room temperature for one hour A mixture of thiobenzoic acid ( 7 5 g) and potassium carbonate ( 4 8 g) in 30 water ( 50 ml) is added and the mixture is stirred overnight at room temperature.

After acidification with concentrated hydrochloric acid, the aqueous solution is extracted with ethyl acetate and the organic phase is washed with water, dried and concentrated to dryness to give I l 2 (benzoylthio) 3 (methoxycarbonyl) propanoyll L proline 35 Example 46

1-l 2 Mercapto-3-(methoxycarbonylmethyl)propanoyl)-L-proline By substituting 1 l 2 (benzoylthio) 3 (methoxycarbonyl) propanoyl L proline for the 1 l 3 (acetylthio) 2 (methoxycarbonylmethyl)propanoyll L proline in the procedure of Example 4, 40 1 l 2 mercapto 3 (methoxycarbonylmethyl)propanoyll L proline is obtained.

Example 47

N-l 3-M ercapto-2-(methoxycarbonylmethyl)propanoyll-Nmethyl-L-phenylalanine 45 By substituting N methyl L phenylalanine for the S (N ethylcarbamoyl) L cysteine in the procedure of Example 28, and then submitting the product to the procedure of Example 29, N l 3 mercapto 2 (methoxycarbonylmethyl)propanoyll N methyl L phenylalanine is obtained 50 Example 48

1-l 3-Acetylthio-2-(cyanomethyl)propanoyll -L-proline I l 3 Acetylthio 2 (cyanomethyl)propanoyll L proline tert butyl ester ( 2 1 g) and p-toluene sulfonic acid ( 0 500 g) are dissolved in benzene ( 25 ml) and the solution is refluxed for 30 minutes The solvent is removed in vacuo, the 55 residue is dissolved in ethyl acetate, washed twice with water, dried and concentrated to dryness The residue is chromatographed on silica gel with benzene:acetic acid ( 75:25), yield 0 85 g R,:0 18 (silica gel:benzene:acetic acid 75:25).

1._ 589 _ 011 1 r\

Claims

WHAT WE CLAIM IS:

1 A compound of the formula X (CH 2), A B l I I R-S (CH 2)m-CH-CO-N-CH-CO-R or such a compound in salt form, wherein R is hydroxy or lower alkoxy; R, is hydrogen, lower alkanoyl, benzoyl or 5 X (CH 2)n A B I I I -S-CH 2)m-CH-CO-N-CH-CO-R A is hydrogen, lower alkyl or hydroxy-lower alkyl; B is hydrogen, lower alkyl, phenyl, phenyl lower alkyl, hydroxy lower alkyl, hydroxyphenyllower alkyl, amino-lower alkyl, guanidinolower alkyl, imidazoyl-lower alkyl, indolyl-lower alkyl, mercapto-lower 10 alkyl, lower alkylthio-lower alkyl, carbamoyl-lower alkyl or carboxylower alkyl; or A and B together form a (CH 2), bridge which completes a ring of 5 or 6 atoms with the nitrogen and carbon to which they are joined one carbon of said ring optionally being substituted with a hydroxy group; X is carboxy, lower alkoxycarbonyl, carbamoyl, N-substituted carbamoyl 15 wherein the N-substituent is lower alkyl or phenyl-lower alkyl or cyano; mis O or 1; n is 0, 1, 2, 3 or 4; and p is 3 or 4.

2 A compound as in Claim I wherein R is hydroxy; 20 R, is hydrogen or lower alkanoyl; X is lower alkoxycarbonyl or carbamoyl; A is hydrogen; B is lower alkyl, amino-lower alkyl or phenyl-lower alkyl; or A and B join to complete a 5 or 6-membered ring; m is I and N is 1 or 2.

3 A compound of the formula R,-5-(c N 2),,-CH-CO-N-c H-CO-R 25 or such a compound in salt form, wherein R, R, X, m and N have the same meaning as in Claim 1.

4 A compound of the formula or such a compound in salt form, wherein R, R,, X, m and N have the same meaning 30 as in Claim 2.

A compound as in Claim 1 wherein A B I I -N-CH-CO-R is the radical derived from glycine, alanine, leucine, threonine, phenylglycine, phenylalanine, lysine, arginine, glutamine, histidine, methionine, serine, cysteine, 35 tyrosine, valine, asparagine, glutamic acid, proline, hydroxyproline, tryptophane, or N-methylphenylalinine.

6 A compound as in Claim I wherein A and B together are-(CH 2)4 completing a six-membered ring.

1,589,933 7 A compound as in Claim I wherein R, is X (CH 2)n A B -S-(CH 2)m-CH-CO-N-CH-CO-R wherein R, A, B, X, m and N have the same meaning as in Claim 1.

8 A compound as in Claim 1, 3, 5, 6 or 7 wherein X is carboxy.

9 A compound as in Claim 1, 3, 5, 6 or 7 wherein X is lower alkoxycarbonyl 5 A compound as in Claim 1, 3, 5, 6 or 7 wherein X is carbamoyl.

11 A compound as in Claim 1, 3, 5, 6 or 7 wherein X is cyano.

12 A compound as in Claim 3 wherein R is hydroxy; R 1 is hydrogen; X is methoxycarbonyl; and m and N each is 1.

13 A compound as in Claim 3 wherein R is hydroxy; R 1 is hydrogen; X is 10 carbamoyl; and N and m each is 1.

14 A compound as in Claim 3 wherein R is hydroxy; R 1 is hydrogen; X is cyano; and m and N each is 1.

A compound as in Claim I as named in any of Examples 2-6, 10, 12, 14 27 and 29-48 15 16 A pharmaceutical composition comprising a compound as in any preceding claim and a pharmaceutical carrier.

17 A composition as in Claim 16, in the form of a tablet capsule or elixir, or a sterile solution or suspension for parenteral administration.

18 A composition as in Claim 16 or 17 which includes a binder, preservative 20 stabiliser or flavor.

For the Applicants, D YOUNG & CO Chartered Patent Agents, 9 & 10 Staple Inn, London WCIV 7RD.

Printed for Her Majesty's Stationery Office, by the Courier Press, Leamington Spa, 1981 Published by The Patent Office, 25 Southampton Buildings, London, WC 2 A l AY, from which copies may be obtained.

1,589,933